As one of the characteristic service of the mobile communication system, the location service is always considered to be a bright spot of the mobile value-added service in the future. At present, the main mobile communication operators of the countries and areas, such as, North America, Europe, and the Asian-Pacific, etc., already provide the mobile location service. The location service is the most attractive service in the mobile value-added service, and also is one of the most complicated service in each part of the industry chain at the same time.
LOC is established by incorporating the work of the LIF forum, the location service in the Wireless Access Protocol (WAP) forum, and the third stage relevant work of the Location Services (LCS) of the 3rd Partner Project (3GPP) Release 6 (R6) by the Open Mobile Architecture (OMA) in 2002, of which the objective is to realize establishing the interconnection and intercommunication location service standard, establishing the specification of the mobile location service, and ensuring the interoperation from end to end. At present, the OMA LOC is replacing the 3GPP and 3GPP2 progressively in the research field, such as, roaming and the Le interface, etc., and becomes the main international specification framer of the location service standard. The main work of the OMA LOC is to establish the location technology based on the User plane in the mobile communication network, realize transmitting, in the IP channel, the relevant location parameter in the control plane location technology in the former mobile communication network, and then realize the location, and reduce the reliance on the core network at the same time, reduce the coupling, and increase the flexibility. With the constant development of the requirement, the OMA LOC also studies on how to provide the location service for the non-mobile communication network progressively, such as, the location of the fixed access way, the location of the Internet way, the location of the WLAN way, etc.
At present, according to the Secure User Plane Location (SUPL) technology defined by the Open Mobile Architecture (OMA) location group (LOC), this location system is mainly composed of three function entities, which are the SUPL Agent, the SUPL server, that is, the SUPL Location Platform (SLP) and the SUPL Enabled Terminal (SET) respectively.
In the SUPL location system, the relation among the above-mentioned three function entities is shown in FIG. 1. The principle of the current SUPL location technology is described by combining the accompanying FIG. 1 hereinafter:
the SUPL-enabled Terminal (SET) is the located SET, which establishes the SUPL location conversation connection with the SUPL location platform through the User Datagram Protocol (UDP)/Internet Protocol (IP) way, and the corresponding function interface is the Lup interface, and the protocol is the SUPL protocol. Through the SUPL protocol, the location information of the SET can be obtained.
The SET can include one Mobile Location Services (MLS) application, or SUPL agent. Both the MLS application and the SUPL agent can request the SET to perform the location service through the private interface on the SET, or the interface comply with the Mobile Location Protocol (MLP).
The Le/L1 interface is adopted between the SUPL location platform and the mobile location application\SUPL agent of the network side, and the protocol is MLP or LOC SIP. The function is that: the third party location application system\the SUPL agent requests the SUPL location platform to locate the SET service through the Le/L1 interface.
The SUPL location platform includes two function entities, which respectively are: the SUPL Location Center (SLC) and the SUPL Positioning Centre (SPC). When the SUPL location platform works by the non-agent way, the SLC and the SPC are separated, and have one individual interface relation with the SET respectively; when it works by the agent way, there is only one function interface between the SUPL location platform and the SET, that is, the interface between the SLC and the SET, and there is no interface between the SPC and the SET, the SLC serves as the agents of the SPC and the SET, and the interface between the SLC and the SPC is the LIP. Because of the roaming of the SET, the SUPL location platform may respectively serve as the function roles such as: the roaming location platform, the request location platform, the home location platform, and the urgent location platform, etc. The corresponding SLC and SPC all have these function roles.
Besides the above-mentioned description, the SUPL location platform also supports other interfaces, such as: the roaming interface between the platforms, the interface between the platform and the calculation server, the interface between the platform and the privacy server, the interface between the platform and the network layer.
The SUPL agent can provide one function of accessing the location service to the application, which is the first service access point provided for the outside by the location service system. The application locates one or more SETs through the SUPL agent request.
At present, the SET, except being able to access the Public Land Mobile Network (PLMN), also can access the local access network, for example, accessing the Wireless Local Area Network (WLAN), or xDSL\FTTx network. In different communication networks, the location technologies are different from each other, for example, in the PLMN, the location technology of 3GPP LCS and the location technology of OMA SUPL can be adopted, while in the local access network the location technology of IETF HELD can be adopted. The PLMN location described in the present invention, under the situation which is not specially illustrated, means the location based on the SUPL, as shown in FIG. 2:
when the SET can access the PLMN and the local access network at the same time, the SET can select the location service provided by the PLMN and also can select the location service of the local access network to perform location. The network of which the location server is adopted to perform location may be decided by a plurality of factors, such as, location accuracy, location representation way, and the expenses, etc.
For the PLMN location service, the technology is already ripe at present. For example, for the 3GPP network, the SET can adopt the location method based on the control plane, and also can adopt the location method based on the user plane.
When the SET can find the location server of the local access network by itself and signs the location service with the local access network, the SET at this moment can totally determine to use the location service of which network independently. At this moment, the relation between the location service of the local location network and the location service provided by the PLMN is the competitive relation.
It can be seen from FIG. 2, when the SET uses the location service provided by the local access network directly, there is no any relation between the SET and the SLP server based on the PLMN. The two location systems are totally independent.
For the operator of the PLMN, they hope that no matter the user of the Home Network accesses the PLMN or other local access networks, the user can access the location service conveniently. When the user accesses the local access network, since the location service provided by the local access network may meet the user requirement even more, at this moment the operator hopes the user can also use the location service of the local access network in a situation that the user does not sign the service with the local access network.
The OMA LOC group defines that the SET always requests the location service from the home location server, and obtains the location service, and the user can only use the home location server but cannot use the location service of the local access network when accessing other local access networks, which impacts the user experience.